Interlocking sheet-piling



July 2, 1935. s c s 2,006,721

INTERLOCKING SHEET FILING Filed Feb. 23, 1935 2 Sheets-Sheet l a frzverz 01:

July 2, 1935. M. SACHS 2,006,721

INTERLOCKING SHEET PILING Filed Feb. 23, 1935 2 Sheets-Sheet 2 fmrenior:

ML; 'M f 4 Patented July 2, 1935 UNITED STATES PATENT. OFFICE Application February 23, 1935, Serial No. 7,904 In Austria March 20, 1934 8 Claims.

This invention relates to interlocking sheetpiling in sections of Z profile, and has for its object to increase the efficiency of sheet-piling of this nature, that is to say to obtain an increase in moment of resistance for a given weight of material used.

Interlocking sheet-piling made up of rolled section material of Z-shaped profile is already known in a variety of designs. In these known designs of sheet-piling, as with all section material comprising webs and flanges, there is a recognized standard ratio between the proportion of material concentrated in the webs on the one hand and that concentrated in the flanges on the other hand. This ratio has become established on the basis of practical experience and of theoretical considerations. Theoretically, as little material as possible should be concentrated in the webs and as much as possible in the flanges and that in such a manner that the webs are as thin and high as possible and the flanges as thick and broad as possible, since these conditions make for the maximum moment of resistance. However, considerations of resistance to breaking strain set a limit to the height of the webs for a given thickness, since, as is well known, the resistance to breaking strain decreases with the square of the height.

The present invention provides interlocking sheet-piling of Z profile the essential feature of which is that the distance of the flanges from the axis of the piling wall increases with their clearance from the web. The flanges, which are thus disposed at an angle to the axis of the piling wall, may be rectilinear, curved, or polygonal in shape.

Forms of construction embodying the invention are shown, by way of example, in the accompanying drawings, in which:

Figs. 1 to 4 show four varieties of profile in accordance with the invention, in section.

Fig. 5 shows two elements of the sheet-piling according to the invention in the interlocked condition, likewise in section.

Figs. 6 and 7 show detail modifications, in diagrammatic representation.

Referring to the drawings, the sheet-piling sections of Z profile according to the invention consist essentially of the web I and flanges 2. In accordance with the invention the flanges are not parallel but inclined at an angle a (see Fig. 1) to the middle axis or axis of symmetry 3. If this proflle be compared with one in which the height of the web is the same but in which the flanges are parallel to the axis, with the same thicknesses of material in the web and flange,

the projected length of the type according to the invention being assumed to be the same as the actual length of the type with which it is compared, it will be found that the Z profile proposed by the present invention implies but a very slight increase in the amount of material required, this increase being dependent on the size of the angle 0:. Since cos 8 amounts to approximately 0.99, the extra amount of material used in the flanges of the profile according to the present invention, when this angle is adopted, is approximately 1%. The situation is very different as regards moment of resistance. This factor is increased, given the usual dimensions, and having regard for the fact that the material concentrated at the interlocking portion 4 is also further removed from the axis 3, by some to according to the size of the profile concerned.

With on increase of 1% in the amount of material used there is thus obtained an increase in moment of resistance amounting to 25 to 30%. This relation becomes still more favorable when the angle a is larger.

In Fig. 2 the Z profile according to the invention is shown with curved flanges, and in Fig. 3 with polygonal flanges.

According to Fig. l the two adjacent interlocking piles meet at 5 at an obtuse angle (1802oz). In order to obtain plane surfaces capable of bearing flat against plane surfaces lying parallel to the axis of the piling wall the ends 6 of the flanges may be disposed parallel to this axis, as shown in Fig. 4.

When once the thicknesses of the flanges and webs and the heights of the Z profiles are determined, the moment of resistance can be varied by setting the webs closer or wider apart per unit of length of the piling wall. If the height of the webs (see Fig. 5) be denoted by h and the breadth of the flanges by b, the ratio bzh is valid for estimating the value for the moment of resistance. In all cases for which bzh 1 the moment of resistance is more favorable than in the cases for which b:h 1, since the flange participates to a relatively greater extent than the web in determining the moment of resistance. If the more unfavorable cases be eliminated, this means that the breadth of the flange or (with curved, polygonal, or inclined flanges) its projection on the plane of symmetry of the piling wall, must be greater than or at least equal to the height of the web.

In order that the invention may be utilized to the full, the once attained distance of a flange element from the axis must not be allowed to become reduced at the next following element, since otherwise the gain in moment of resistance would in part become lost again. It often occurs with Z profiles that a gap becomes left between the abutting surfaces on the flange ends of adjacent interlocking piles, with the result that a depression is formed. This is very disadvantageous, since in accordance with the invention precisely those masses of the material are concentrated which contribute most to the increasing of the moment of resistance. For this reason the abutting surfaces of the interlocking flange ends should flt closely together as at 1 (Fig. 5).

If the flange be so designed that its outer surface is at a larger angle of inclination to the piling wall axis than the inner surface the flange will be continuously tapered out from the web or from the wall axis upto the end or to the terminal portion of the flanges disposed parallel to the wall axis. With a profile deslgned'in this manner a, higher moment of resistance is obtained without the use of more material, than with a Z profile in which the sides of the flanges are disposed parallel to each other.

In Fig. 6 there is shown, in full lines, one half of the cross-section of a Z proflle of this nature. The angle on is larger than the angle as. It will at once be clear that the moment of resistance of a Z profile of this nature, given the use of equal amounts of material, is greater than that of a pr'ofile having parallel sided flanges (indicated by a complementary broken' line in Fig. 6), since masses are displaced from a position I of lower moment of resistance to a position II of higher moment of resistance.

In Fig. 'I there is shown one half of the crosssection of a Z profile in accordance with the invention in which the continuous tapering out of the flanges extends only up to the flange ends disposed parallel to the wall axis.

I claim:

1. Interlocking sheet-piling consisting of 2 pro-' file sections in which the distance of the flange elements from the plane of symmetry of the piling increases with their clearance from the web of the same section. I

2. Interlocking sheet-piling as claimed in claim 1 in which the said flanges are of rectilinear configuration and disposed at an angle to the plane of symmetry of the piling.

3. Interlocking sheet-piling as claimed in claim 1 in which the said flanges are inclined over the greater part of their length at an angle to the plane of symmetry of the piling, the outer terminal portions of the said flanges being disposed parallel to the said plane.

4. Interlocking sheet-piling as claimed in claim 1 in which the breadth of each of the said flanges, measured in projection on the plane of symmetry of the piling, is at least equal to the height of the web pertaining to the same section of the said piling.

5. Interlocking sheet-piling as claimed in claim 1 in which the breadth of each of the said flanges, measured in projection on the plane of symmetry of the piling, is greater than the height of the web pertaining to the same section of the said p ling.

6. In interlocking sheet-piling as claimed in claimed in claim 1 abutting surfaces on the interlocking ends of the flanges of each of the said sections adapted to flt closely together when the said sections are in the interlocked condition.

7. Interlocking sheet-piling as claimed in claim 1 in which each of the said flanges is tapered out continuously from the web to the outer end.

8. Interlocking sheet-piling as claimed in claim 1 in which each of the said flanges has an outer terminal portion disposed parallel to the axis of symmetry of the said piling and is tapered out continuously from the web to the commencement of the said terminal portion.

MAXIMILIAN SACHS. 

